Whose water is it? Water rights in the age of scarcity.

Who “owns” what water? Or, if water belongs to the public, who has the right to use it?

This question is perhaps the thorniest question in the world of water. The answer is critical to California’s growing water crisis. It is critical to water in the western U.S. It is critical to the spat between Alabama, Georgia, and Florida over the Apalachicola-Chattahoochee-Flint river system (say that three times fast). It is critical to Egypt and the nine other nations that share the Nile. It is critical to the Israelis, Palestinians, Jordanians, Lebanese, and Syrians who share the tiny Jordan River. It is critical to disputes among users of water around the world.

And feelings run high. Just last week, Governor Sonny Purdue of Georgia said that Georgia has a right to all the water that originates in the state and that falls in the state and will fight to keep it. “The state of Georgia is due the use of that water, and we will make use of that water,” the Governor said. He was responding to a recent major court ruling that said that Georgia is using more water than it should under current law and agreements, depriving Florida and Alabama of its equitable share. I wrote about this in my July 17 post.

This is an old idea — the water falls here or runs through here so why can’t I use all of it? At the grandest scale, this idea is called “The Harmon Doctrine,” which says that upstream water users have the right to do whatever they want with the water in their own “territory” no matter what harm it causes to downstream users. It was named after a U.S. Attorney General in the 1890s who said that Mexico had no right to any water that originates in the U.S., even if the river flows into Mexico. The only problem for Governor Purdue, and Georgia, is that the Harmon Doctrine has been universally repudiated: in international law, in U.S. law, and in any ethical or moral set of rules.

Just think about what it would mean to apply the Harmon Doctrine. Egypt would have no right to any of the water of the Nile, which originates entirely in the upstream nations (including Burundi). Yet the Nile supplies 97% of Egypt’s water. California, Nevada, Arizona, New Mexico, Utah would have no right to any Colorado River water (except tiny flows that join the river lower down) because most of it comes from the Rocky Mountains in Colorado. Turkey would not have to deliver a drop of water to the Tigris and Euphrates rivers, which also sustain Syria and Iraq. China wouldn’t have to share their flows of the Mekong, the Ganges/Brahmaputra, the Salween, and the other major rivers that sustain billions of people in Asia. That is a recipe for chaos and, frankly, war. All rational water laws and management policies have long acknowledged that downstream parties have rights.

But upstream parties have rights too. The opposite idea of the Harmon Doctrine — that upstream states have no right to use water that would flow naturally to downstream users (the concept of “absolute territorial integrity”) — is also universally repudiated.

And so what are we left with? Laws, customs, and traditions that require us to actually talk with each other, to discuss and negotiate how to manage and efficiently use shared water resources. The seven Colorado River states have an agreement for sharing, and we have a treaty with Mexico. The Israelis and the Jordanians have a water agreement. The Nile River basin countries are talking about a new sharing arrangement. These agreements are imperfect, but they are far better than no agreements at all, and imperfect agreements can be improved.

It is time for Georgia, or China, or any water users in places where water is no longer abundant to stop posturing and start discussing how to share our rivers and our groundwater too. Just because you are first on a river, or upstream, or own a piece of land with groundwater does not mean that you have no responsibilities to other users, including non-human users, sharing the same watershed. Your use affects others. We may believe that these water resources are not connected to each other or that the use by one person has no effect on their neighbors or that the first user should have senior rights forever. And in the past this may have worked. But if we continue to use 20th century rules to solve 21st century water problems, conflicts over water will only worsen.